Apparatus for burning sulphur



Feb. 18, 1936. M. s. MAXIM APPARATUS FOR BURNING SULFHUB Filed June l5, 1931 2 Sheets-Sheet 1 Feb. 18, 1936.

M. S. MAXIM APPARATUS FOR BURNING SULPHUR Filed June l5, 1931 2 Sheets-Sheet 2 HTTOPNEK which may be preferred;

Patented Feb. 18, 1936 UNlTED 'STATS PATENT OFFICE 7 Claims.

'Ihis invention relates to the combustion of sulphur to sulphur dioxide for use in the manufacture of suiphuric anhydride, calcium bisulphite, etc.

Heretofore, sulphur has been burned by drawing air over a pool of molten sulphur. This procedure is objectionable, however, in that the rate of combustion as well as concentration of the sulphur dioxide gas cannot be controlled accurately, and the presence of impurities in the sulphur interferes with the normal combustion of the molten elemental sulphur. Moreover, the operation of the burner cannot be interrupted quickly and a period of time will always lapse during which residual sulphur which is present in the burner volatilizes and may burn only partially resulting in deposition of elemental sulphur in the system and polution of the surrounding atmosphere with sulphur dioxide vapors.

It has likewise been proposed to inject a spray of atomized sulphur into a combustion chamber provided with a source of primary .and secondary air. This procedure necessitates a source of compressed air for atomization purposes or a supply of compressed molten sulphur, which is divided into fine particles by causing the same to iiow through a suitable nozzle.

One object of this invention is to provide an apparatus for burning unatomized molten sulphur or solid sulphur whereby it is volatilized or combusted practically instantaneously, thereby avoiding the presence of molten sulphur in the burner system.

A further object of the invention is to provide an .apparatus for burning sulphur which does not require a supply of molten Sulphur maintained at substantial pressures and which avoids the necessity of a spray or nozzle mechanism.

A further object of the invention is to provide an apparatus for burning sulphur whereby one 'is enabled to maintain easily conditions and gas concentrations without careful and continued supervision.

The invention likewise contemplates structural features which afford ease of control and operation, and which will be more apparent by referring to the .accompanying drawings and the description of apparatus and operation thereof set forth more fully hereinafter.

Figure 1 is a sectional elevational view of an embodiment of the principles of the invention and E 'igure 2 likewise is a sectional, elevational View of a burner embodying certain modifications not disclosed in Figure l.

The structure illustrated in Figure 1 consists of .a cylindrical steel shell (I0), which is lined with a refractory material (Il), such as re- The cylinder is provided with a pipe (Irl) is formed integrally with the head by which air is introduced through the head into an air compartment (IIS) formed bythe nead (I3) and a tile arch (Il) within the cylinder. The arch is provided with an aperture (I 8) in the center thereof, through which the primary air passes from the air compartment into a sulphur burner chamber (I9) below. A small iron pipe (2|) which supplies liquid sulphur to the burner projects through the head (I3) and aperture (I8) and discharges into the sulphur burner compartment. p

Within the 'sulphur burner compartment a trapezoidal brick checker work (22) having a hollow pyramidal central portion is disposed on a tile base (23). A sulphur distributor plate (24) rests on the top of the brick checker work and immediately below the discharge end of thesulphur feed pipe. The arrangement of the bricks forming the checker work is such that the molten sulphur does not fall through the voids any substantial distance without engaging a brick surface. It is to be noted that the primary air must flowV through the voids in the checker work.` The base or iioor of the sulphur burner chamber'is constructed of refractory material which is'supported on a ledge (Z5) of the wall (I I) and by an arch (3|). Interconnecting the sulphurburner chamber and a combustion chamber `(26) a passageway (2l) is provided having a plurality of ports (28) along its circumference through which secondary air is introduced into the gas stream. A space (29) between the base of the burner chamber and the arch (3|) of the combustion chamber functions as a manifold for secondary air that is suppliedthrough the ports and intimately mixed withthe gases fromA the burner compartment. Directly below the passageway a second refractory checker work (32) is disposed to receive any molten sulphur which might W into the combustion chamber. Although under ordinary operating conditions the sulphur is probably volatilized completely and almost immediately within the burner chamben'4 `er chamber (I9). Vture (400-.450 C.) has thus been attained within should any molten sulphur find its way into the combustionphamber it will distribute itself over the checker work and avoid formation of a pool of sulphur at the base of the combustion chamber. The gases are discharged from the combustion chamber through an aperture (33) near the base of a vertical completely enclosed passage- 'Way (34) constructed within the chamber and connected near its upper extremity to a discharge port (35) in the cylinder. Accumulated noncombustible matter may be removed conveniently through an opening (31) at the base of the combustion chamber by first removing the cover plate therefrom. Alternatively, if desired, the gases from the burner may be discharged from Vthe combustion chamber through a por-t (42), the port (35) being closed.

A burner of the type illustrated, having a diameter of 10-12 feet and a height of 18-22 feetwill be found adequate to burn forty tons of sulphur per day. For this purpose a brick checker work in the combustion chamber having approximately 125.0 square feet of surface has been found sufricient.

In operating the burner, it is convenient to Aheat the structure primarily by means of oil or kgas until a. temperature of approximately 400- 450 C. is attained. For this purpose there are provided three or four gas jet apertures disposed circumferentially of the chamber (23) and near the base thereof 'as at (38); similarly three orl four apertures are provided forr to heat the burn- After an operating temperathe structure,.the Vjet openings and combusted gas discharge aperture (4i) are closed. Thereafter the Amolten sulphur is fed through the pipe at a regulated rate. Primary air is supplied in an amount `to provide sufficient heat within the burner chamber to oxidize or vaporize the sulphur promptly. Suiicient Vsecondary air is mixed with the `gas dischargedfrom the chamber to produce a gas of the desired concentration. Air which has previously been dried may be employed if desired.

After the burner has attainedits normal operating temperature, the heat content of the structure is sufficient to interrupt the koperation of the burner for as much as l2 hours without the necessity of preheatingthe -structure byV means of gas. Interruption of .the operation of the burner results in no inconvenience inasmuch as the sulphur in the system at any time is burned completely within a minute after the. supply of liquid sulphur is terminated. The combustion has been found to be complete and no residual sulphur accumulates in the base of the burner or Vcombustion chamber. From time to time an accumulation within the combustion chamber of non-combustible impurities present in the sulphur may be Yremoved conveniently through the door at the base.

No stoppage of the nozzle or spray difficulties are encountered. Moreover, the molten sulphur supplied to the burner is at no time under substantial pressures, such as is requiredinV the operation of a nozzle for the purpose of atomizing the sulphur. The division of the primary and secondary air is such as to afford temperature control and at the same time avoid overheating of the burner elements. The burner includes no mechanically operated parts nor any delicate elements requiring close adjustment. The apportionment of the primary and secondary air may 'a baiiie Wall (52).

be effected conveniently by conventional valves or dampers. Y V

The structure illustrated in Figure 2 consists of a steel shell (4S) which is lined with refractory material (fil) similar to that'in Figure l. Molten sulphur is introduced through a pipe (48) projected into the cylinder and near one extremity thereof. Directly below the pipe there is disposed a checker Work (49) over which the sulphur distributes itself. Primary air is supplied through a pipe (5I) below the checker work and is caused to rise upwardly therethrough, and over Y The gaseous mixture which flows over the baiile is mixed with secondary air that is admitted through a port (53) adjacent the sulphur feed, and is mixed intimately there- With as it passes downwardly between the bale and atile partition (54) provided with apertures at its base, interconnecting the passageway with a combustion chamber (56) wherein the combustion of the `svrlpliur iscompleted. The SO2 gases are discharged Ythrough a port k5l.

The operation of this burner is analogous to that illustrated in Figure 1. The preliminary heating may be eiected by means of gas o-r oil supplied4 through Yjet openings (58) in the usual manner, the gases resulting therefrom being discharged through arport (59), after which the ports (58) Yand (59) .are closed and molten sulphur is supplied to the burner at a regulated rate 'together with the required quantities of primaryand secondary air. The Vquantity of air is adjusted toY assure prompt and complete combustion o-r volatilization of the sulphur as well as to eliminate overheating of the checker work zone.

The checkerwork serves a multiple function in that it not only affords a large surface with which the sulphur must contact and thereby exposes a large area of sulphur to oxidation, but inraddition it affords a large capacity for the storage of the heat of combustion, thus insuring uniformity of operation as well as an adequate highly heated surface for the volatilization and .promotion of the combustion at temperatures above those normally realized in a burner wherein the surface is wetted completely by molten sulphur and wherein the temperature is limited to a large extent by the presence of the molten sulphur. Y

In lieu of the molten sulphur feed pipe one may substitute a screw feed mechanism adapted to handle .solid sulphur. To this end a closed hopper is disposed above the burner, which is provided at its base with a screw mechanism i that is adapted to discharge directly into the burner, Fluxing of the sulphur in the screw feed Vis avoided by adequate heatV insulation or by means of water cooled sulphur feedv elements.

Inasmuch as .the chamber is under a slight positive vpressure the hopper should be constructed to sustain an equivalent pressure. The hopper maybe filled periodically from a second hopper disposed above the'rst, which likewise is constructed to sustain a slight internal pressure.

After the second hopper has discharged into the first the means interconnecting the two hoppers is closed in order that the pressure within the secondy hopper-may be Vreleased and an additional charge of sulphur may be introduced pre-y paratory for refilling the rst hopper.

The solid sulphur supplied by the screw feed deposits upon the checker work and is volatilized and partially combusted almost immediately. In

' otherrespects the operation'of the unit equipped for solid sulphur is the same as in the case of liquid sulphur.

From the description hereinabove set forth, it should be apparent to those skilled in the art that by this invention I have provided an apparatus for burning sulphur` at superatmospheric pressures without the necessity of a spray or atomizing unit; that the concentration of the combusted sulphur gases is easily controlled by appropriate adjustment of the air or sulphur supply; that the nuisance caused by reason of the presence of pools of molten sulphur as well as the fluctuation in gas strengths caused thereby is eliminated; and that the apparatus is simple, inexpensive and easily operated. It will likewise be apparent that although I have illustrated and described two embodiments of the invention, one being of a vertical design and the other of a horizontal design, the invention is susceptible to numerable modications without departing from the principles thereof which contemplate broadly the combination of a pressure burner adapted to utilize sulphur while avoiding the necessity of atomization or intimate subdivision of the sulphur to be combusted.

What I claim is:

1. An apparatus for burning sulphur comprising a chamber having a horizontal partition dividing it into an upper sulphur burning compartment and a lower combustion compartment, means for supplying sulphur to the sulphur burning compartment, inlet means for supplying air to said compartment, said partition having an opening formed therein providing communication between the two compartments, a refractory checker work disposed below and in line with the opening, to receive unvaporized sulphur dropping from the first compartment, and an inlet means for supplying secondary air to the second cornpartment.

2. An apparatus for burning sulphur as dened in claim l in which the inlet for secondary air is provided intermediate the upper and the lower compartments.

3. An apparatus for burning sulphur comprising a chamber having a horizontal partition dividing it into upper and lower compartments,

functioning respectively as a sulphur burning compartment and a combustion compartment, means for supplying sulphur to the sulphur burning compartment, an inlet for air to said compartment, said partition having an opening formed therein providing a passageway from one compartment to the other, a refractory checker work in the upper compartment disposed directly over and straddling the opening in the partition, the checker work also being disposed to receive sulphur from the sulphur supplying means and an inlet for secondary air to theY lower compartment.

4. An apparatus as dened in claim 3 in which an additional refractory checker work is disposed in the lower compartment below and in line with the opening in the partitionto receive sulphur dropping therethrough.

5. An apparatus for burning sulphur comprising a horizontal chamber having spaced partitions vertically disposed therein dividing it into a sulphur burning compartment and a combustion compartment, a refractory checker work disposed inthe sulphur burning compartment, an inlet disposed above the checker work for depositing sulphur thereupon, an air inlet in the chamber for supplying air to the sulphur burning compartment, openings formed in the spaced partitions providing a passageway for gases from the sulphur burning compartment to the combustion chamber, an inlet through the walls of the chamber communicating with the space between the partitions for admitting air thereto, whereby to cool the partitions and to dilute the gases from the sulphur burning compartment.

6. An apparatus for burning sulphur comprising a chamber having two spaced partitions disposed therein dividing it into a sulphur burning compartment and a combustion compartment, said partitions having a passageway formed therein inter-connecting the two compartments, a conduit supplying air to the space between the two partitions, ports for conducting the air into the stream of gases flowing through the passageway, the space between the partitions together with the ports constituting a manifold structure for the distribution of air to the gases in the passageway, and inlets for supplying sulphur and primary air to the sulphur burning compartment.

l 7. An apparatus for burning sulphur comprising an elongated chamber having. a pair of spaced partitions transversely disposed therein dividing the chamber into a sulphur burning compartment and a combustion compartment, the two compartments being interconnected by openings through the partitions, an inlet for primary air to the sulphur burning compartment, the latter compartment also being provided with a refractory checkerwork disposed to provide a forarninous barrier between the inlet for primary air and the openings through the partitions and through which the primary air must pass to reach said openings, a feeding device disposed above the checkerwork to supply sulphur thereto, and an inlet for secondary air disposed to discharge a current of air into the space between the two partitions.

MYLES STANDISH MAXIM. 

